Bayliss . — On the Galvanotropism of Roots. 
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— to — 1 ampere they produced a curvature to one or other 
150,000 150,000 
electrode according to its position. 
Of 13 seedlings, in which the positive and negative electrodes were 
placed exactly opposite one another, at about 1*5 mm. to 2 mm. from the 
root apex, 8 curved to the positive electrode, 4 curved to the negative 
electrode, and 1 between the two : there was frequently blackening and 
signs of injury, more especially at the place where the positive electrode 
touched. 
To add more resistance and thus still further weaken the current, 
the electrodes were placed 1-5 cm. or more apart ; and now the curvature 
was towards the apical electrode, whether positive or negative, and usually 
there was no sign of injury. The results from 15 seedlings tested in this 
way, during 15 nearly consecutive days, gave 13 curvatures to the apical 
electrode, whether positive or negative. Two only died ; the others showed 
no sign of injury. 
4 b. Results with Strong Currents. 
With strong currents of 3 to 8 minutes duration voltage 4-2 and 
resistance that of the root tissue only, the results were as follows : — 
a. With electrodes on opposite sides, at a distance from the apex 
varying from 1-5 to 5 mm., out of 29 radicles, 27 curved to the positive 
electrode, 1 remained straight, and the other curved to the negative 
electrode. 
ft. With electrodes on opposite sides, one placed 1-5 mm. from the 
apex and the other 5 to 10 mm. away, out of 21 radicles, 12 curved to 
the apical electrode, whether positive or negative, 4 remained straight, 
3 curved in the opposite direction, and 2 were doubtful. 
y. With electrodes on the same side of the root, one 1*5 or 2 mm. from 
the apex, and the other varying from 5 mm. to 4 cm. away, out of 69 seed- 
lings, 37 curved to the apical electrode, 14 curved away, 20 did not curve, 
and the other three died. 
S. With one electrode flat against the apex, and the other 1-5 to 3 mm. 
away, out of 33 seedlings, 16 curved to the current side (7 only slightly), 
16 did not curve, 1 curved away. 
e. With one electrode flat against the apex, and the other more than 
5 mm. away, out of 9 radicles none curved. 
It was quite possible to get these positive and negative curvatures 
without visible injury to the root, even when examined microscopically, 
although in some cases the epidermis and perhaps one or two cortical 
layers of cells were injured, and in a few the injury extended even to 
the stele. 
